264 Tue MICROSCOPE. 
b With a cellular, dark brown annulus (c). 
b With a cellular, purplish-blue, iridescent annulus,* . . 
Paludicella, 
¢ Extremities rounded, . . . . . . Plumatella, Fig. 2. 
ce Extremities acute, sometimes prolonged . . .. . 
Lophopus, Figs. 3 and 4. 
dad Spines in a single, marginal series, double-hooked,. . . 
Pectinatella, Fig. 5. 
d pines in two rows, variously hooked, 54a) tale 
Cristatella, Figs. 6 and 7. 
TRENTON, N. J. 
NOTES ON THE MICROSCOPE STAND, AND SOME OF 
ITS ACCESSORIES. 
AN AMATEUR. 
THE FOOT OR BASE. 
PON the material, whether brass or iron, from which the foot 
is made depends some of the cost of the stand and much of 
the weight, both being worth considering. So far as utility is con- 
cerned iron is as acceptable as brass, less attractive in appearance, 
and cheaper. It has been said that iron is as good for this pur- 
pose as brass provided the stand is not dropped, when an iron 
foot would be more likely to be broken. The man who drops 
his microscope, and risks such an accident, in my opinion does 
not deserve to have a microscope. A microscopist should be the 
most careful and patient of human beings. The beginner need 
never reject an otherwise acceptable stand because the foot is not 
of brass, but he should look to its form. 
Most of the foreign stands, notably the modern ones of Zeiss, 
have the foot horse-shoe shaped, which fortunately has not be- 
come the custom among American opticians. The form is 
clumsy, ugly, and in no way essential to steadiness. To obtain 
the needed weight without too greatly enlarging the horse-shoe, 
it is made very thick, and to keep the stand properly balanced 
when inclined, the pillar is inserted close to the curve, leaving 
the two sides extending off into space as far as they are able, 
always reminding me of those people who try to grasp the unat- 
tainable and to reach after the infinite, while if they should cul- 
tivate a little more common sense, and be a little more practical, 
* Parfitt. Ann. and Mag. Nat. Hist. 1866. p. 171. 
} Not yet observed in this country. 
